The preparation of dialkyl peroxides by the reaction of an alcohol such as tert-butyl alcohol (t-BA) with an organic hydroperoxide such as tertiary hydroperoxide (t-BHP) is known. See, for example, U.S. Pat. Nos. 2,403,771; 2,862,973; and 3,6626,014. The preparation of dialkyl peroxides by the reaction of an olefin such as isobutylene with an organic hydroperoxide such as tBHP is also known. See Davies, et al., J. Chem. Soc., 2200–2204, 1954. Also, French Pat. No. 1,555,308 shows the reaction of isobutylene with hydrogen peroxide to produce tBHP and di-tert-butyl peroxide. In such prior art processes, there have been employed soluble acid catalysts such as hydrogen bromide, sulfuric acid, soluble heteropoly acids, soluble isopoly acids and sulfonic acid resins having a high gel phase porosity, which also have a low degree of cross-linking and swell upon hydration, thereby reducing the amount of available acidity within such catalysts.
However, the use of such catalysts brings with it a number of serious disadvantages, including the high cost of the complex processing needed to recover the diallyl peroxide; the high cost of recovering the soluble catalyst; the pervasive cost, extensive corrosion, and significant safety hazards associated with the use of sulfuric acid; the use of boron-containing esters; the use of extraneous and environmentally undesirable solvents; and catalyst deactivation and deterioration, which is characteristic of catalyst resins. Canadian Pat. No. 839,312, for example, shows the production of di-tert-butyl peroxide by the reaction of t-BA and t-BHP using a gel-type 4% cross-linked resin, with the requirement that water be azeotropically removed, e.g., with chloroform, in order for the reaction to proceed. The use of heterogeneous acid catalysts with readily available acidity for organic reactions avoids all of the above-mentioned disadvantages.
Di-tert-butyl peroxide is a chemical agent and additive which has experienced a low volume of sales due to its high market price. This has resulted in a limitation on its current use for potentially a significant number of diverse specialty purposes. One of these purposes is in the manufacture of ethylene glycol (EG), a staple of commerce and a raw material for other end products, which has many end uses and is produced in immense quantities annually. Di-tert-butyl peroxide has been shown by the applicant herein to be highly effective and efficient in the production of ethylene glycol and propylene glycol (PG). See, e.g., U.S. Pats. Nos. 4,337,371; 4,393,252; 4,412,084; and 4,412,085. Ethylene glycol is a highly important article of worldwide commerce not only for its own properties, but for its role as well, when condensed with terephthalic acid on an equimolar amount, to produce polyethylene terephthalate (PET), from methanol alone and/or from methanol and formaldehyde.
In order for di-tert-butyl peroxide to find application and utility in the large scale manufacturing of ethylene glycol, or to become a successful candidate for other low cost uses such as in clean-burning diesel fuel as an very high cetane diesel fuel blending component, costly processing and purification reforms will have to be effected in the above-described production techniques for di-tert-butyl peroxide. Although methods have been suggested for the production and recovery of di-tert-butyl peroxide, as indicated, there remains considerable room for improvement in the efficiency and economics of the technology for producing di-tert-butyl peroxide. Unfortunately, the complex and costly processing methods which have been suggested in the prior art to date, cannot produce di-tert-butyl peroxide at a sufficiently low cost to permit its applicability to use in large volume, low cost methanol-based ethylene glycol and propylene glycol production, or to use as an very high cetane diesel fuel blending component.